1. Statement of the Technical Field
The inventive arrangements relate to point cloud data, and more particularly to compression and filling of gaps in point cloud data.
2. Description of the Related Art
LiDAR is a three dimensional (3D) sensing system that can generate 3D image data. The system works by recording multiple range echoes from pulses of laser light to generate an image frame. Such data is comprised of a collection of points in three dimensions which correspond to the multiple range echoes within a sensor aperture. Data recorded by a LiDAR system is sometimes referred to as a three dimensional point cloud data. The data points in a 3D point cloud data are sometimes referred to as “voxels” which represent a data point value on a regular grid in three dimensional space. Voxels used in 3D imaging are analogous to pixels used to in the context of 2D imaging devices. In this regard, it should be understood that each data point in the 3D point cloud typically has an individual x, y and z value, such that the point cloud can represent the actual surface within a scene in 3D. Each point can also have an intensity value. With the foregoing information, LiDAR data can be processed to reconstruct a three-dimensional representation of a surface or terrain.
LiDAR data can be collected at sub-meter distances between data points. Accuracy increases with higher resolution, since more points are available to define the features to be modeled. Gaps in LiDAR data impact the quality of image products generated using such data. Gaps in LiDAR data can occur for various reasons. For example, since laser scanning requires good reflectivity at the target surface, gaps may occur due to multi-path reflections. Also, some grid posts may be recorded without heights/ranges, and areas of data gaps or voids can arise as a result. Due to these and other phenomena, existing data collections frequently tend to have voids. Data collection service providers often claim a particular point density based on number of points collected per square area. Although on average these claims are valid, the data voids or gaps can significantly degrade derived products.